<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006~2018 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: zhangyajun <448901948@qq.com>
// +----------------------------------------------------------------------

namespace app\common\library;

use think\Paginator;

class LayPage extends Paginator
{

    /**
     * 上一页按钮
     * @param string $text
     * @return string
     */
    protected function getPreviousButton($text = "上一页")
    {

        if($this->currentPage() <= 1)
        {
            return $this->getDisabledTextWrapper($text);
        }
        return $this->getPageLinkWrapper($this->currentPage() - 1, $text);
    }

    /**
     * 下一页按钮
     * @param string $text
     * @return string
     */
    protected function getNextButton($text = '下一页')
    {
        if(!$this->hasMore)
        {
            return $this->getDisabledTextWrapper($text);
        }

        return $this->getPageLinkWrapper($this->currentPage() + 1, $text);
    }

    public function getUrlRange($start, $end)
    {
        $urls = [];

        for($page = $start; $page <= $end; $page++)
        {
            $urls[$page] = $page;
        }

        return $urls;
    }

    /**
     * 页码按钮
     * @return string
     */
    protected function getLinks()
    {
        if($this->simple)
            return '';

        $block = [
            'first' => null,
            'slider' => null,
            'last' => null
        ];

        $side = 3;
        $window = $side * 2;

        if($this->lastPage < $window + 6)
        {
            $block['first'] = $this->getUrlRange(1, $this->lastPage);
        }
        else if($this->currentPage <= $window)
        {
            $block['first'] = $this->getUrlRange(1, $window + 2);
            $block['last'] = $this->getUrlRange($this->lastPage - 1, $this->lastPage);
        }
        else if($this->currentPage > ($this->lastPage - $window))
        {
            $block['first'] = $this->getUrlRange(1, 2);
            $block['last'] = $this->getUrlRange($this->lastPage - ($window + 2), $this->lastPage);
        }
        else
        {
            $block['first'] = $this->getUrlRange(1, 2);
            $block['slider'] = $this->getUrlRange($this->currentPage - $side, $this->currentPage + $side);
            $block['last'] = $this->getUrlRange($this->lastPage - 1, $this->lastPage);
        }
        $html = '';

        if(is_array($block['first']))
        {
            $html .= $this->getUrlLinks($block['first']);
        }

        if(is_array($block['slider']))
        {
            $html .= $this->getDots();
            $html .= $this->getUrlLinks($block['slider']);
        }

        if(is_array($block['last']))
        {
            $html .= $this->getDots();
            $html .= $this->getUrlLinks($block['last']);
        }

        return $html;
    }

    /**
     * 总数
     * @return int|null|string
     */
    protected function getTotalText()
    {
        return '<span class="layui-laypage-skip">共 ' . $this->total . ' 条</span>';
    }


    protected function getSelectText()
    {
        return '<span class="layui-laypage-skip" style="margin-left: 0;">' . $this->listRows() . ' 条/页</span>';
    }

    protected function getInputText()
    {
        $html = '<span class="layui-laypage-skip">到第';
        $html .= ' <input type="number" min="1" max="' . $this->lastPage . '" value="1" class="layui-input">页';
        $html .= ' <button type="button" class="layui-laypage-btn" style="color:#333;">确定</button>';
        $html .= ' </span>';
        return $html;
    }

    /**
     * 渲染分页html
     * @return mixed
     */
    public function render()
    {
        if($this->hasPages() || config('paginate.show_page'))
        {
            if($this->simple)
            {
                return sprintf(
                    '<div class="layui-box layui-laypage layui-laypage-page ">%s %s %s</div>',
                    $this->getPreviousButton(),
                    $this->getLinks(),
                    $this->getNextButton()
                );
            }
            else
            {
                return sprintf(
                    '<div class="layui-box layui-laypage layui-laypage-page ">%s %s %s %s %s %s</div>',
                    $this->getTotalText(),
                    $this->getSelectText(),
                    $this->getPreviousButton(),
                    $this->getLinks(),
                    $this->getNextButton(),
                    $this->getInputText()
                );
            }
        }
    }

    /**
     * 生成一个可点击的按钮
     *
     * @param  string $url
     * @param  int $page
     * @return string
     */
    protected function getAvailablePageWrapper($page, $text)
    {
        return '<a href="javascript:;" lay-page="' . $page . '">' . $text . '</a>';
    }

    /**
     * 生成一个禁用的按钮
     *
     * @param  string $text
     * @return string
     */
    protected function getDisabledTextWrapper($text)
    {
        return '<a href="javascript:;" class="layui-laypage-prev layui-disabled">' . $text . '</a>';
        //return '<li class="disabled"><span>' . $text . '</span></li>';
    }

    /**
     * 生成一个激活的按钮
     *
     * @param  string $text
     * @return string
     */
    protected function getActivePageWrapper($text)
    {
        return '<span class="layui-laypage-curr"><em class="layui-laypage-em" style="background-color:#1E9FFF;"></em><em>' . $text . '</em></span>';
    }

    /**
     * 生成省略号按钮
     *
     * @return string
     */
    protected function getDots()
    {
        return $this->getDisabledTextWrapper('...');
    }

    /**
     * 批量生成页码按钮.
     *
     * @param  array $urls
     * @return string
     */
    protected function getUrlLinks(array $urls)
    {
        $html = '';

        foreach($urls as $page => $url)
        {
            $html .= $this->getPageLinkWrapper($url, $page);
        }

        return $html;
    }

    /**
     * 生成普通页码按钮
     *
     * @param  string $url
     * @param  int $page
     * @return string
     */
    protected function getPageLinkWrapper($url, $page)
    {
        if($page == $this->currentPage())
        {
            return $this->getActivePageWrapper($page);
        }

        return $this->getAvailablePageWrapper($url, $page);
    }
}
